Acoustic generators using a piezoelectric element have been conventionally known (for example, see Patent Literature 1). Such an acoustic generator outputs sound by applying a voltage to a piezoelectric element mounted on a vibrating plate, thereby causing the vibrating plate to vibrate to actively use resonance of the vibration.
In addition, such an acoustic generator can be formed thin and with a light weight in comparison with common electromagnetic speakers, because a thin film such as a resin film can be used as the vibrating plate.
In the case of using a thin film as the vibrating plate, the thin film requires support in a state of being provided with uniform tension by being held in a thickness direction between, for example, a pair of frame members, to obtain excellent acoustic conversion efficiency.